实现了观察者模式的用户控件。
在学习 IssueVision 过程中，提到过观察者模式的用户控件(ChartPanel?)，我按自己的设计思路也做了个不伦不类的观察者模式+用户控件，记录下来。
首先，建立一个观察者模式的接口 IObserver.cs
using System;using System.Collections.Generic;using System.Text;namespace IssueVision
{
public interface IObserver //接口声明
{ void NotifyDataChange(ChartData nChartData); //事件，当数据改变时
} //ChartData 类，表示三类事务，open,work,close public class ChartData { private int n_open; private int n_work; private int n_close; private int n_max; public int open { get { return n_open; } set { n_open = value > 0 ? value : 0; n_max = value > n_max ? value : n_max; } } public int work { get { return n_work; } set { n_work = value > 0 ? value : 0; n_max = value > n_max ? value : n_max; } } public int close { get { return n_close; } set { n_close = value > 0 ? value : 0; n_max = value > n_max ? value : n_max; } } public int max { get { return n_max; } set { n_max = value > 0 ? value : 0; } } }
}
接着声明主体 ISubject.cs
using System;using System.Collections.Generic;using System.Text;namespace IssueVision{ public interface ISubject //声明主体接口 { // 需实现这两个，实现注册和反注册 void Register(IObserver anObject); void UnRegister(IObserver anObject); }}
现在新建一个用户控件，放上一个 lbltitle 表示标题，三个 label 分别表示 open , work , close，再放三个 progressbar 表示数量，因为懒得画条形图，所以直接用 progressbar ， 不过，用 progressbar 很难看倒是真的:(。，用户控件叫 ChartPanel.cs，代码如下
using System;using System.Collections.Generic;using System.ComponentModel;using System.Drawing;using System.Data;using System.Text;using System.Windows.Forms;namespace IssueVision.UserControls{ public partial class ChartPanel : UserControl , IObserver //指定 IObserver ，表示实现它 { private string m_title; private int n_max; private int n_open; private int n_working; private int n_closed; [Description("图表标题")] public string Title { get { return m_title; } set { m_title = value; Invalidate(); } } [Description("最大数量")] public int NMAX { get { return n_max; } set { n_max = value > 0 ? value : 0; Invalidate(); } } [Description("打开任务数量")] public int NOpen { get { return n_open; } set { n_open = value > 0 ? value : 0; Invalidate(); } } [Description("进行的任务数量")] public int NWorking { get { return n_working; } set { n_working = value > 0 ? value : 0; Invalidate(); } } [Description("关闭的任务数量")] public int NClosed { get { return n_closed; } set { n_closed = value > 0 ? value : 0; Invalidate(); } } public void NotifyDataChange(ChartData nChartData) //实现观察者的 NotifyDataChage，表示当接受到数据变更时应用的动作。 { // n_max = nChartData.max; n_open = nChartData.open; n_working = nChartData.work; n_closed = nChartData.close; Invalidate(); } public ChartPanel() { InitializeComponent(); } private void ChartPanel_Paint(object sender, PaintEventArgs e) { this.lbTitle.Text = m_title; pbOpen.Minimum = 0; pbWorking.Minimum = 0; pbClosed.Minimum = 0; pbOpen.Maximum = n_max; pbWorking.Maximum = n_max; pbClosed.Maximum = n_max; pbOpen.Value = n_open > n_max ? n_max : n_open; pbWorking.Value = n_working > n_max ? n_max : n_working; pbClosed.Value = n_closed > n_max ? n_max : n_closed; } }}
下面是设计器形成的，ChartPanel的设计代码，一并留下
namespace IssueVision.UserControls{ partial class ChartPanel { /// <summary> /// 必需的设计器变量。 /// </summary> private System.ComponentModel.IContainer components = null; /// <summary> /// 清理所有正在使用的资源。 /// </summary> /// <param name="disposing">如果应释放托管资源，为 true；否则为 false。</param> protected override void Dispose(bool disposing) { if (disposing && (components != null)) { components.Dispose(); } base.Dispose(disposing); }
组件设计器生成的代码 private System.Windows.Forms.Panel pnlTop; private System.Windows.Forms.Label lbTitle; private System.Windows.Forms.Label lblOpen; private System.Windows.Forms.Label lblWorking; private System.Windows.Forms.Label lblclosed; private System.Windows.Forms.ProgressBar pbOpen; private System.Windows.Forms.ProgressBar pbWorking; private System.Windows.Forms.ProgressBar pbClosed; }}新建一个窗体，放上刚才的用户控件 chartpanel1,放置 textbox2,3,4 ，放一个按钮。
public class SubjectImpl:ISubject //被观察者的实现 { protected Hashtable _observerContaind = new Hashtable(); public void Register(IObserver anObserver) { _observerContaind.Add(anObserver,anObserver); } public void UnRegister(IObserver anObserver) { _observerContaind.Remove(anObserver); } public void NotifyObservers(ChartData n_data) { foreach (IObserver anObserver in _observerContaind.Keys) { anObserver.NotifyDataChange(n_data); } } } public class MyData :SubjectImpl { private ChartData _cd = new ChartData(); public ChartData CD { get { return _cd; } set { _cd = value; base.NotifyObservers(_cd); } } }
private void button1_Click(object sender, EventArgs e) { ChartData mycd=new ChartData(); mycd.open=Convert.ToInt16(textBox2.Text); mycd.work=Convert.ToInt16(textBox3.Text); mycd.close=Convert.ToInt16(textBox4.Text); MyData md = new MyData(); md.Register(chartPanel1); md.CD = mycd; }
呼，终于完了，点此 button 后，chartpanel 将会更改，不过，这么做会不会太麻烦了？
